During the last decade there has been a growing interest in the effects of electrical stimulation on bone remodeling, and investigators have used a number of different techniques to stimulate bone growth and remodeling. There has also been speculation that the electromechanical effect in bone (the production of an electric polarization by and applied stress) may be involved in bone remodeling. However, in spite of this interest in the electrical properties of bone, we still know relatively little about the dielectric properties of fluid saturated bone. This is surprising because the dielectric properties of bone will determine, in part, the current paths and the relationship between the local current and the local electric fields in bone and adjacent tissue during electrical stimulation. The dielectric properties can also have a large effect on the electromechanical properties of bone. Therefore, we need to know the dielectric properties of bone in order to analyze and understand how electrical stimulation and the electromechanical effect influence bone remodeling. In view of the importance of the dielectric properties for understanding the effects of electrical stimulation and the nature of the electromechanical effect, we propose to measure the dielectric properties of fluid saturated bone under various circumstances in order to fully characterize the dielectric properties. We will also do structural studies in order to relate the dielectric properties of bone to its microstructure. The results of these studies will help us to model the currents and electric fields produced during electrical stimulation, and help us understand the electromechanical effect in bone.